The present invention relates to a thermosensitive image transfer recording medium capable of yielding images with high thermal sensitivity and with excellent image gradation on a receiving sheet by application of heat to a thermofusible ink layer of the recording medium through a thermal head or the like so as to imagewise transfer a coloring agent contained in the ink layer to the receiving sheet, thereby forming recorded images on the receiving sheet. More particularly, the present invention relates to a thermosensitive image transfer recording medium comprising a support material and a thermofusible ink layer formed thereon, which thermofusible ink layer comprises an image gradation control agent, a coloring agent and a carrier material, all of which are contained in a fine porous resin structure.
Conventionally, there are known a thermosensitive image transfer sheet comprising a support material and a sublimable dye layer formed on the support material, and a thermosensitive image transfer sheet comprising a support material and a thermofusible ink layer comprising a thermofusible material and a pigment, capable of forming images on a receiving sheet by subjecting the thermosensitive image transfer medium to thermal printing.
However, the method which uses a sublimable dye is superior in image gradation reproduction, but is low in thermal sensitivity and has the drawback of inferior durability of the image. On the other hand, the method which uses a thermofusible material and a pigment is superior in thermosensitivity and the durability of the produced images, but has the drawback of providing poor image gradation.